I believe this is the road where the collision happened, although not sure of the precise location, possibly not too far from the start as another article said it was near Uniondale. http://goo.gl/maps/zKEAs

Pulling together all the details from the three articles mentioned above, it seems to me that the biggest issue was that the rider behind him was following too closely for the conditions (gravel, dust) and ended up hitting him. Kevin fell probably due to momentarily not paying attention for whatever reason, that happens. But typicaly a fall on a flat gravel road at 60MPH when wearing protective gear is not fatal on its own. And that's why they are looking into a case of culpable homicide, which to me sounds a lot like what in the States would be negligent behavior resulting in death, or maybe even involuntary manslaughter.

A terrible accident. i have ridden those roads many times, a beautiful, amazing place - but you need to keep your wits about you. My condolences to the family... we have lost a great colleague.
Glenn Foley
Dirt and Trail magazine
South Africa